LXR toybox/toys/net/microcom.c

   1/* microcom.c - Simple serial console.
   2 *
   3 * Copyright 2017 The Android Open Source Project.
   4
   5USE_MICROCOM(NEWTOY(microcom, "<1>1s#=115200X", TOYFLAG_USR|TOYFLAG_BIN))
   6
   7config MICROCOM
   8  bool "microcom"
   9  default y
  10  help
  11    usage: microcom [-s SPEED] [-X] DEVICE
  12
  13    Simple serial console.
  14
  15    -s  Set baud rate to SPEED (default 115200)
  16    -X  Ignore ^@ (send break) and ^] (exit)
  17*/
  18
  19#define FOR_microcom
  20#include "toys.h"
  21
  22GLOBALS(
  23  long s;
  24
  25  int fd, stok;
  26  struct termios old_stdin, old_fd;
  27)
  28
  29// TODO: tty_sigreset outputs ansi escape sequences, how to disable?
  30static void restore_states(int i)
  31{
  32  if (TT.stok) tcsetattr(0, TCSAFLUSH, &TT.old_stdin);
  33  tcsetattr(TT.fd, TCSAFLUSH, &TT.old_fd);
  34}
  35
  36void microcom_main(void)
  37{
  38  struct termios tio;
  39  struct pollfd fds[2];
  40  int i;
  41
  42  // Open with O_NDELAY, but switch back to blocking for reads.
  43  TT.fd = xopen(*toys.optargs, O_RDWR | O_NOCTTY | O_NDELAY);
  44  if (-1==(i = fcntl(TT.fd, F_GETFL, 0)) || fcntl(TT.fd, F_SETFL, i&~O_NDELAY)
  45      || tcgetattr(TT.fd, &TT.old_fd))
  46    perror_exit_raw(*toys.optargs);
  47
  48  // Set both input and output to raw mode.
  49  memcpy(&tio, &TT.old_fd, sizeof(struct termios));
  50  cfmakeraw(&tio);
  51  xsetspeed(&tio, TT.s);
  52  if (tcsetattr(TT.fd, TCSAFLUSH, &tio)) perror_exit("set speed");
  53  if (!set_terminal(0, 1, 0, &TT.old_stdin)) TT.stok++;
  54  // ...and arrange to restore things, however we may exit.
  55  sigatexit(restore_states);
  56
  57  fds[0].fd = TT.fd;
  58  fds[1].fd = 0;
  59  fds[0].events = fds[1].events = POLLIN;
  60
  61  while (poll(fds, 2, -1) > 0) {
  62
  63    // Read from connection, write to stdout.
  64    if (fds[0].revents) {
  65      if (0 < (i = read(TT.fd, toybuf, sizeof(toybuf)))) xwrite(0, toybuf, i);
  66      else break;
  67    }
  68
  69    // Read from stdin, write to connection.
  70    if (fds[1].revents) {
  71      if (read(0, toybuf, 1) != 1) break;
  72      if (!FLAG(X)) {
  73        if (!*toybuf) {
  74          tcsendbreak(TT.fd, 0);
  75          continue;
  76        } else if (*toybuf == (']'-'@')) break;
  77      }
  78      xwrite(TT.fd, toybuf, 1);
  79    }
  80  }
  81}
  82